Alluvial Fan Flooding
NFIP Policy Index
Definition/Description
Flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flowpaths. Alluvial fan flooding is depicted on a Flood Insurance Rate Map (FIRM) as Zone AO, with a flood depth and velocity.
NFIP Requirement
Guidance
- IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP) (Page 1-14) and Regulatory Standards (page 6-28)
- CRS Commentary Supplement for Special Hazards Credit
Related Keywords
Special Topic Resources
Last Modified: Thursday, 04-Jun-2009 13:47:06 EDT